Foundry molding box



-May 6, 1930. A. B. SMITH ET-A FOUNDRY MQLDING BOX Fild A ril 6, 1929 2Sheets-Sheet 1 INVE- mks. A .B.sm;m.

May 6, 1930.

A. B. SMITH ET AL FOUNDRY MOLDING BOX Filed April 6, 1929 2 Sheets-Shee2 ATTE- Patented May 6, 1930 NIT D srA'r' s fP 'Aranror-rica ALFREDBARTLETT SMITH AND omrronn ROSS-SMITH, OFWOLVERHAMPTON,

, ENGLAND.

roonnnx MOLDING 302;

Application filed April 6, 1929, Serial No. 353,080, and in GreatBritain April 16, 1928.

This invention relates to improvementsin molding boxes and the like andrefers par-.

ticularly to molding boxes, core boxes, metallic molds for, die-castingand the like of the type in which a number of boxes or molds may berequired to be superimposed and accurately located and secured togetherto form a complete amold. c

a In foundry work, it is a common practice to w m assemble a number ofsuch boxes and locate them relatively to each other by'a number ofseparate and, in many cases, staggered connections or location devices]This is commonly done by means of pins rigidly attached to one partengaging holes or lugs on an adjacent part or by means of loose pinsengaging holes or lugs or adj acent parts. In

some cases the pins and holes are cylindrical;

in others they are V-shaped; butin any case 2 the connection isduplicated between each of the several boxes in one complete mold. Itwill therefore by obvious, as there must be a small amount of playbetween eachiattach ment pin and the lugs or holes with which it 7 isengaged, that in a deep casting, molded in a number of boxes, there mustbe a cumulative error of quite serious proportions. This error must beallowed for in the casting, and on a machined section on a casting maynecessi- 3 tate correspondingly greater labour in machining and. lossesin metal on the finished work while on an unmachined section on acasting allowance must be made for possible inaccuracies whencalculating the thickness or other dimensions.

With location or connection means which function only between adjacentboxes, or a pair of boxes, it is difiicult to maintain anaccurate fit ofan attachment pin and the box 4o lugs, forrthe reason that theparallelism of the bores of the lugs cannot be -either'commerlcially,produced or maintained for these purposes in their strict right-anglerelationship to the plane ofthe box-part. Accordingly,

- clearances have to be allowed, and. if such clearances as aregenerally employed are re- 7 duced, then, owing to the entry of dust andfine grains of sand which are trapped between the working surfaces ofthe pin and hole,ex-

5o 1 cessive binding is caused in assemblyand useunderactualfoundryconditions. The forcusual and known methods oflocation are empl ye a, -p It is an object of our invention to enablecommon attachment and'locating members to beemployed with a range ofseveral boxes andto render each box quite standard as .to its lugs andattachment means so that-not only is a coaxial location of thevariousboxes possible,butfalso a" complete interchangeability of allboxes comprising a range or set .is obtained Another object istoaccomp1ish;this in such a manner that, although the tolerance betweenthe common member and the lug of any individual box is smaller bling theboxes in superposed relation and accuracy 1s mamtained over a longperiod of use. a

in a flange serving the same purpose, and the bores .inthe lugs, or theapertures in the 'flange, are mere clearances formed larger than thepin-member on which the boxes are to Ifit, and thereuponare adjustablysecured knife" edged or nose-edged location plates which can be set withaccuracy to accommodate the locating :pin member.

areeach V shaped to give a four point contact each oflinedepthonly onthe pin member, while at the other side two parallel edgedstripsdirected parallel with the axis of the ,box which passes throughthe lugs, and spaced to give a line contact on two opposite sides of.the pin, will sufiice.

:The combination of these location plates having knife or, nose edgedcontact lines with an accurately made and gauged, hard, cylindricalpin-common to all the box parts is'a useful, practical embodimentensuring greater than hitherto,lthere isno difficultyin assem- Theselocation plates at one side of the box 3 or'Figure 4.

accuracy of work and economy in labour and metal. j V

These improved location devices are automatically self-clearing, as sandgrains cannot be trapped between the pinand these line contactlocationplates; there is no'binding therefore, a much closer fitting pincan be worked easily and smoothly, wear is reduced and great accuracyispermitted and maintained.

We make use of two sets of location plates on each box, one set near thetop. and one set near the bottom. This ensures that the box surface andthe axes of the pins are held truly at right angles to each other. Whileit isnot essential to make this provision oneach end of each box part ofa pair or set of boxes, when working on flat or hollow" surfaced molds,it is always necessary with one of such parts, and therefore incommercial use we prefer to make it a standard practice. In theaccompanying drawings Figure 1 is a perspective view of a box;

Figure 2, is a central longitudinal section thereof on a larger scale.

Figure 3, is a plan of one part of the location plates which. are shownat the-left hand end of Figure 1.

Figure. 4, is a planrof oneof the-plates shown at the right hand end ofFigure 1.

Figure 5, is a section on line 5. 5 of Figure In this illustratedexample we formfleach box with two lugs a at'each end, 'onenear the topand the other near the bottom, opposing lugs at the two ends being inthesame planes. In each lug is a clearance apertureb large enough to passfreely the pins on which all the boxes are to work. on the faces of thelugs a which are remote from each otheigwe secure at one end two pairsof location plates 0 Figure 3, and at the other'end' two pairs of platescl Figure 4. The plates 0 are; eachV- shaped in their ends and they areassembled with their V ends oppositeeachother, but

separated sufliciently for the four inclined lines thus produced to fitthe cylindrical locating pins, which are to be used with them,

with the smallest working clearance. We find in our own foundry practicethis clearance may be reduced to0.0005 v(five.ten-thousandths) of aninch on a pinof 1" diameter. Eachangular edge 'e of these Vshap'ed endsis formed in themanner shown in Figure 5.

" The lugs a at the other end of the box are a similarly provided'withpairs oflocation plates (Z each of which has an edge. f, ,of sectioncorresponding to Figure 5,. along one end. These knife edged ends fareassembled opposite each other, separated s'ufiiciently to fit acylindrical pin at twolopposite points only under the same conditions ofaccuracy at these points as in the case of the plates 0. The holes in.the lugs for the reception of the attachment bolts 9 for the locationthe other end of said the plates 0 and the two edges 7 of the plates 1 dmust be set in the same relative position in each box if all the boxesof a set are to be interchangeable and capableof use: on a truecylindrical pin at each end common to all the box parts. For-thesetting'of these plates any suitable jig giving this result canbeemploy'ed as will be clear to those skilledin the art. A-jig havingmasterpins, setfor the various siz'esof boxes is a'c onvenient method,the pins being gauged to a size larger thanthe actual pins on whichthe'boxes-are td'work by the extent of the clearance allowed! It ispreferred, but is notessentialgto' cast the location plates c anddfandformthe egges e as dead hard edges by the 'use' -of c ills. 7 i

The pins for use with the box partillus trated in the drawings arenot'shown as these are merely true'cyl-indiical pins, preferably hardenedsteel ofa length to 'accommodate any required number 'of"boxes insuperposition; i

We claim I 1; Foundry-molding box or' flask comprising in combination aframe part, lugs? on oppositeends of said frame part, clearanceapertures in the lugs, location means adjust ably secured on'said lugs'to loc'atethe: frame partsat-eaclr end'on a. cyliiidrical locationpin passed through said clearance apertures, said location meanslgivm'gPOHIlT "COHtQCt'OTL said pin, said location means atone'end'of saidframe consisting of opposed plates'having V notches in their oppositeedges andat clearance apertures to locatethe frame part at eachend of acylindrical, location; pin

passed through said clearance: apertures, said location plates at oneend of said frame having \l-notches in their opposite edges and at framehaving straight opposite edges; V

3."In foundry molding boxesoriflasksof the kind in"which' a, rectangularbox'lik'e molding part, is" provided ,at' opposite ends with perforatedlugs which cooperate with cylindrical pins'commonto a plurality oftheboxes to locate the boxes in'proper molding relation one with another,the combination with said lugs of apertures which are clearances on thecylindrical pins with which the lugs are to cooperate in locating saidboxes,

plates adjustably secured on the lugs at each end of the box with theends of the plates opposing each other and overlying the clearanceapertures, said overlying opposed ends of said plates being formed withedges giving point contact on the cylindrical plns, and said plates atone end of saidbox part having V notches in their op osing edges thesides of which notches are mife edges; and said plates at the other endof said box part having straight opposed edges longitudinally directed,said straight edges being formed as knife edges.

Intestimony whereof we affix our signatures.

ALFRED BARTLETT SMITH. CLIFFORD ROSS SMITH.

